import numpy as np

if __name__ == '__main__':
    a = np.arange(0, 9).reshape((3,3))
    b = np.arange(9, 18).reshape((3, 3))
    c = np.arange(18, 27).reshape((3, 3))
    d = np.arange(27, 36).reshape((3, 3))
    list1 = []
    list1.append(a)
    list1.append(b)
    list1 = np.array(list1)
    print(list1)
    print(list1.shape)

    list2 = [c,d]
    list2 = np.array(list2)
    print(list2)
    print(list2.shape)

    list3 = np.stack((list1, list2), axis=3)
    print(list3)
    print(list3.shape)